NIVO

NIVO, abbreviated from Night Invisible Varnish Orfordness (or "Night Varnish Orfordness"), was a dark grey-green overall finish applied to British night bomber aircraft in the inter-war period (1918-1939).
Developed in 1918 by the Experimental station at Orfordness, as a low-visibility colouring for the Royal Air Force it had a sheen to match that of open water on a moonlit night.